1. Field of the Invention
The present invention relates to a substrate processing method of and a substrate processing apparatus for cleaning substrates of various types such as semiconductor wafers, glass substrates for photomask, glass substrates for liquid crystal display, glass substrates for plasma display and optical disk substrates.
2. Description of the Related Art
As a conventional solution to remove fine particulate matters (hereinafter referred to simply as “particles”) adhering to surfaces of substrates, a substrate processing apparatus which supplies a processing liquid to a substrate surface and cleans the substrate surface is known. In the apparatus described in Japanese Unexamined Patent Application Publication No. 2001-358108 for instance, a substrate is immersed in a processing liquid to which ultrasonic vibrations are applied for a higher efficiency of cleaning the substrate. Describing in more specific details, ultrasonic vibrations vibrates particles adhering to a substrate and separates the particles off from the substrate surface, or ultrasonic vibrations make cavitations and bubbles created in the processing liquid act upon the substrate, whereby the substrate is physically cleaned.
Another approach for removal of particles adhering to a substrate is cleaning which uses a chemical solution such as SC1 (a mixture solution of aqueous ammonia and aqueous hydrogen peroxide). In the apparatus described in Japanese Unexamined Patent Application Publication No. H11-340185 for instance, a substrate is immersed in a chemical solution bath filled with SC1 and a surface layer of the substrate and particles adhering to the substrate surface are etched and accordingly removed.
Meanwhile, in the apparatus described in Japanese Unexamined Patent Application Publication No. H11-31673, particles adhering to a substrate are frozen together with a liquid, high-pressure pure water or cold pure water is then sprayed over the substrate and an ice film is peeled off from the substrate, whereby the substrate is cleaned.